Small scale fabrication has been dominated over the past 40 years by lithography techniques that employ radiation in the form or visible or ultraviolet light. However, these techniques are limited by the wavelengths of the light used and fabrication below 100 nm is problematic. Electron and ion beam lithography are alternative techniques capable of providing finer resolution but which typically use a serial scanning process that limits the speed of production.
Two additional techniques that have received attention because of their ability to fabricate structures with nanometer resolutions are nanoimprint lithography and scanning probe lithography. These techniques are distinguishable from the typical optical and electron based lithography discussed above in that these tools are proximal in nature and either contact, or are separated by a nanoscopic gap from, the substrate undergoing processing.
Nanoimprint lithography employs a molded stamp structure with grooves formed therein so as to emboss, coat, or otherwise imprint a pattern on a target substrate. However, in repeated use, the stamp structure of the mold may be subject to erosion or soiling over time that can negatively impact the achievable resolution so that nanometer resolution patterning becomes impossible or inconsistent.
Scanning probe lithography techniques employ devices with ultrafine tips to etch, coat, or otherwise treat a substrate so as to generate nanometer resolution patterns. However, scanning probe lithography is also a serial process and is therefore too time consuming to be employed in large scale fabrication.
Chapter 9 of Nanoelectronics and Information Technology (Ed. Rainer Waser, WILEY-VCH, 2003, pgs. 223-247) provides further background details of modern lithography approaches.
The present invention provides a fabrication tool and method to achieve nanometer resolution features which is capable of parallel processing and which may be used repeatedly without significant deterioration or reduction in reliability over time.